FFmpeg 5.1.4
downmix_info.h
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1/*
2 * Copyright (c) 2014 Tim Walker <tdskywalker@gmail.com>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#ifndef AVUTIL_DOWNMIX_INFO_H
22#define AVUTIL_DOWNMIX_INFO_H
23
24#include "frame.h"
25
26/**
27 * @file
28 * audio downmix medatata
29 */
30
31/**
32 * @addtogroup lavu_audio
33 * @{
34 */
35
36/**
37 * @defgroup downmix_info Audio downmix metadata
38 * @{
39 */
40
41/**
42 * Possible downmix types.
43 */
45 AV_DOWNMIX_TYPE_UNKNOWN, /**< Not indicated. */
46 AV_DOWNMIX_TYPE_LORO, /**< Lo/Ro 2-channel downmix (Stereo). */
47 AV_DOWNMIX_TYPE_LTRT, /**< Lt/Rt 2-channel downmix, Dolby Surround compatible. */
48 AV_DOWNMIX_TYPE_DPLII, /**< Lt/Rt 2-channel downmix, Dolby Pro Logic II compatible. */
49 AV_DOWNMIX_TYPE_NB /**< Number of downmix types. Not part of ABI. */
50};
51
52/**
53 * This structure describes optional metadata relevant to a downmix procedure.
54 *
55 * All fields are set by the decoder to the value indicated in the audio
56 * bitstream (if present), or to a "sane" default otherwise.
57 */
58typedef struct AVDownmixInfo {
59 /**
60 * Type of downmix preferred by the mastering engineer.
61 */
63
64 /**
65 * Absolute scale factor representing the nominal level of the center
66 * channel during a regular downmix.
67 */
69
70 /**
71 * Absolute scale factor representing the nominal level of the center
72 * channel during an Lt/Rt compatible downmix.
73 */
75
76 /**
77 * Absolute scale factor representing the nominal level of the surround
78 * channels during a regular downmix.
79 */
81
82 /**
83 * Absolute scale factor representing the nominal level of the surround
84 * channels during an Lt/Rt compatible downmix.
85 */
87
88 /**
89 * Absolute scale factor representing the level at which the LFE data is
90 * mixed into L/R channels during downmixing.
91 */
94
95/**
96 * Get a frame's AV_FRAME_DATA_DOWNMIX_INFO side data for editing.
97 *
98 * If the side data is absent, it is created and added to the frame.
99 *
100 * @param frame the frame for which the side data is to be obtained or created
101 *
102 * @return the AVDownmixInfo structure to be edited by the caller, or NULL if
103 * the structure cannot be allocated.
104 */
106
107/**
108 * @}
109 */
110
111/**
112 * @}
113 */
114
115#endif /* AVUTIL_DOWNMIX_INFO_H */
static AVFrame * frame
reference-counted frame API
AVDownmixType
Possible downmix types.
Definition: downmix_info.h:44
AVDownmixInfo * av_downmix_info_update_side_data(AVFrame *frame)
Get a frame's AV_FRAME_DATA_DOWNMIX_INFO side data for editing.
@ AV_DOWNMIX_TYPE_UNKNOWN
Not indicated.
Definition: downmix_info.h:45
@ AV_DOWNMIX_TYPE_LTRT
Lt/Rt 2-channel downmix, Dolby Surround compatible.
Definition: downmix_info.h:47
@ AV_DOWNMIX_TYPE_LORO
Lo/Ro 2-channel downmix (Stereo).
Definition: downmix_info.h:46
@ AV_DOWNMIX_TYPE_DPLII
Lt/Rt 2-channel downmix, Dolby Pro Logic II compatible.
Definition: downmix_info.h:48
@ AV_DOWNMIX_TYPE_NB
Number of downmix types.
Definition: downmix_info.h:49
This structure describes optional metadata relevant to a downmix procedure.
Definition: downmix_info.h:58
double lfe_mix_level
Absolute scale factor representing the level at which the LFE data is mixed into L/R channels during ...
Definition: downmix_info.h:92
double surround_mix_level_ltrt
Absolute scale factor representing the nominal level of the surround channels during an Lt/Rt compati...
Definition: downmix_info.h:86
double surround_mix_level
Absolute scale factor representing the nominal level of the surround channels during a regular downmi...
Definition: downmix_info.h:80
double center_mix_level
Absolute scale factor representing the nominal level of the center channel during a regular downmix.
Definition: downmix_info.h:68
enum AVDownmixType preferred_downmix_type
Type of downmix preferred by the mastering engineer.
Definition: downmix_info.h:62
double center_mix_level_ltrt
Absolute scale factor representing the nominal level of the center channel during an Lt/Rt compatible...
Definition: downmix_info.h:74
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325